A method for fabricating a forming-free resistive random-access memory (RRAM) device is provided. The method includes: fabricating an RRAM cell and annealing the RRAM cell. The RRAM cell includes: a bottom electrode, a switching oxide layer comprising at least one transition metal oxide; a top electrode, and an interface between the switching oxide layer and the top electrode. In some embodiments, the at least one transition metal oxide includes at least one of HfOx or TaOy, wherein x≤2.0, and wherein y≤2.5. The interface layer comprises a layer of at least one of Al2O3, MgO, Y2O3, or La2O3. The forming-free RRAM device may be switched to multiple resistance levels without a forming process.